1. the capacity to influence others, even when they try to resist this influence. Social power derives from a number of sources: control over rewards (reward power) and punishments or other force (coercive power); a right to require and demand obedience (legitimate power); others’ identification with, attraction to, or respect for the powerholder (referent power); others’ belief that the powerholder possesses superior skills and abilities (expert power); and the powerholder’s access to and use of informational resources (informational power).

2. a measure of how effective a statistical procedure is at identifying real differences between populations: It is the probability that use of the procedure will lead to the null hypothesis of no effect being rejected when the alternative hypothesis is true. For example, if a given statistical test has a power of .70, then there is a 70% probability that its use will result in the null hypothesis correctly being rejected as false, with a corresponding 30% chance that its use will lead to a Type II error. Power ranges from 0 to 1, with values of .80 or above generally considered acceptable.

3. a mathematical notation that indicates the number of times a quantity is multiplied by itself.